Preparation

Make the cookies:

• Position a rack in the center of the oven and heat the oven to 350°F. Line two cookie sheets with parchment or nonstick baking liners.
• In a stand mixer fitted with a paddle attachment or in a large mixing bowl using a hand-held electric mixer, beat the butter, confectioners’ sugar, vanilla, and salt on medium speed until well blended and smooth, about 3 minutes. Scrape down the bowl and beater. Add the flour and mix on low speed until a soft dough forms, about 1 minute.
• Using two teaspoon measures, scoop up about two tsp. of dough at a time, and using your palms, roll into smooth balls that are 1 to 1-1/4 inches in diameter. Arrange them about 1-1/2 inches apart on the lined cookie sheets. Using the back of a 1/2 tsp. measure, press down into the middle of each mound to make a well that is almost as deep as the dough ball. (If the edges crack or break open, it’s best to reroll and try again—the finished cookie will look better and hold the caramel without leaking).
• Bake one sheet at a time until the tops of the cookies look dry and the edges are golden brown, 15 to 20 minutes. Let the cookies cool on the cookie sheet for 5 minutes and then transfer them to a rack to cool completely.

Make the caramel filling:

• In a small saucepan, combine the unwrapped caramels and heavy cream. Set the pan over very low heat and cook, stirring constantly, until the caramels have melted and the mixture is smooth, 4 to 6 minutes. Use the caramel while warm.
• Arrange the cooled cookies on a cookie sheet or jelly roll pan. Using a small spoon or spatula, drizzle the warm caramel into each indentation, filling to the rim but not overflowing. Scatter the nuts over the caramel and press lightly into the caramel. Cool completely before storing or serving.

Make Ahead Tips

Baked, unfilled cookies can be frozen for 1 month or stored at room temperature for 5 days. Layer them between parchment or waxed paper in an airtight container. You can fill the cookies up to 3 days ahead. Arrange them on a sheet pan in a single layer and cover tightly with plastic (don’t let it touh the caramel tops). Store at room temperature.